import { outputHTML } from "./";
import path from "path";
import fs from "fs";

const scopedEval = eval;
/**
 * Use JSONX for express view rendering
 * 
 * files ending with anything other than '.json' or '.jsonx' are processed as javascript files. Express templates support template views on the __template property.
 * 
 * @param {string} filePath - path to jsonx express view
 * @param {object} options - property used for express view {locals}
 * @param {object} options.__boundConfig - property used to bind this object for JSONX, can be used to add custom components
 * @param {string} [options.__DOCTYPE="<!DOCTYPE html>"] - html doctype string
 * @param {*} callback
 */
export function __express(filePath?: string, options?: any, callback?: any) {
  try {
    let jsonxModule = options?.__jsonx;
    let isJSON = false;
    if (filePath) {
      isJSON = ([".json",".jsonx"].includes(path.extname(filePath)));
      const jsFile = fs.readFileSync(filePath).toString();
      jsonxModule = (isJSON)
        ? scopedEval(`(${jsFile})`)
        : scopedEval(jsFile);
    }
    const resources = Object.assign({}, options);
    delete resources.__boundConfig;
    delete resources.__DOCTYPE;
    delete resources.__jsonx;
    const context = Object.assign({disableRenderIndexKey:false}, options?.__boundConfig);
    // if (isJSON) context.useJSON = true;
    const jsonxRenderedString = outputHTML.call(context, {
      jsonx: jsonxModule,
      resources
    });
    const template = `${options?.__DOCTYPE || "<!DOCTYPE html>"}
${jsonxRenderedString}`;
    if (typeof callback === "function") callback(null, template);
    else return template;
  } catch (e) {
    if (typeof callback === "function") callback(e);
    else throw e;
  }
}
